Surgeons are often called upon to inspect internal body cavities to diagnose or remedy a medical condition. For example, a surgeon may inspect the calices of a patient's kidney to search for and remove kidney stones.
In the case of kidney inspection and stone removal, the surgeon may need to inspect each of multiple calices of the kidney. FIG. 1 illustrates a typical kidney 10 that is representative of a kidney that a surgeon may need to inspect. As is shown in FIG. 1, the kidney 10 includes an outer capsule 12 that surrounds a renal cortex 14 in which a plurality of minor calices 16 are formed. Each of the minor calices 16 may extend from a major calyx 18 that, in turn, extends from the renal pelvis 20. The renal pelvis 20 is connected to the ureteropelvic junction 22, which leads down to the ureter 24.
To inspect the kidney 10, the surgeon will normally insert a viewing device, such as an endoscope, into each of the calices 16 of the kidney 10 to enable visual inspection of each calyx for stones. Such a viewing device may be inserted into the kidney via the urinary tract. Fluoroscopy may also be used during such a procedure to aid the surgeon in positioning the viewing device in the desired portion of the kidney 10.
It is common for surgeons to use a top-to-bottom approach when inspecting the kidney 10. In such a procedure, the surgeon checks a first calyx 16, determines whether it contains any stones, and, assuming it does not, checks the next calyx. When a stone is discovered, it is fragmented, if necessary, and removed from the calyx 16 using a retrieval device. This process continues from the top 26 of the kidney 10 to the bottom 28 of the kidney until each calyx 16 has been inspected and every stone or stone fragment has been removed. During the process, the surgeon or the surgical staff tracks which calices 16 have been inspected in an effort to ensure that each calyx is checked.
Because there may be many different calices 16 to inspect and because the position of the viewing device can only be inferentially determined from the images captured by the viewing device and any captured fluoroscopic images, it is often difficult for the surgeon to know with any certainty whether a given calyx has or has not been inspected. As a result, the surgeon may revisit one or more calices one or more times to ensure that it has been checked and does not contain any stones. This “double-checking” lengthens the time required to complete the procedure, thereby increasing risk and/or discomfort to the patient.
Even in cases in which the surgeon and staff are careful in keeping track of which calices 16 have been inspected, it is possible for them to make a mistake that results in one or more calices not being inspected. In such a case, one or more stones or stone fragments may remain which can act as seeds for further stone formation.
In cases in which a stone must be fractured before being removed, for instance if the stone is too large to be removed as a single piece, lithotripsy may be performed to break the stone into smaller fragments. When lithotripsy is performed, it is possible for a stone fragment to be propelled into a calyx 16 that has already been checked. If this happens, one or more stones or stone fragments may remain which, again, can act as seeds for further stone formation.